This invention relates to a floppy disk driver controlling circuit for controlling a floppy disk driver including a stepping motor. This invention also relates to a combination of the floppy disk driver and the floppy disk driver controlling circuit.
A floppy disk driver controlling circuit is for use in controlling a floppy disk driver including a stepping motor. The floppy disk driver comprises a stepping motor driver for producing a driving current to drive the stepping motor and a control section for controlling the stepping motor driver.
In a typical conventional floppy disk driver controlling circuit, the stepping motor driver is mainly composed of bipolar transistors while the control section is mainly composed of CMOS transistors. Accordingly, the stepping motor driver and the control section must be individually and separately formed and can not be integrated together. This results in a problem that the floppy disk driver controlling circuit itself can not be reduced in size.
Japanese Unexamined Patent Publication No. 257927/1989 (Tokkai Hei 1-257927) discloses a motor driver device comprising a motor driver circuit for driving a stepping motor and a control circuit for controlling the motor driver circuit. In this motor driver device, both of the motor driver circuit and the control circuit are formed by CMOS transistors. A combination of the motor driver circuit and the control circuit is integrated on a single chip. However, this motor driver device is for use in a camera to drive a stepping motor for opening and closing a shutter. In this connection, the motor driver device is different in the field of art from the above-mentioned floppy disk driver controlling circuit to which this invention is applicable. Therefore, the above-mentioned problem in the conventional floppy disk driver controlling circuit still remains unsolved.